Improvements in explosively actuated fastener driving tools



Jan. 24, 1956 1 BUMlLLER 2,731,636

IMPROVEMENTS IN EXFLOSIVELY. ACTUATED FASTENER DRIVING TOOLS Filed June 26, 1953 INVENTORI TncQuEs BunmLe-R BY:

United States Patent IMPROVEMENTS IN EXPLOSIVELY ACTUATED FASTENER DRIVING TLS Jacques Bumiller, Valence, France, assignor to Societe de Prospection & dlnventions Techniques Spit, Bourg-les- Valence, France, a French company Application June 26, 1953, Serial No. 364,433 Claims priority, application Spain August 20, 1952 3 Claims. (Cl. 1-44.5)

This invention relates to explosively actuated fastener driving tools for driving dowel pin shaped fasteners into hard and compact materials, particularly to tools having a barrel in which is housed the fastener to be propelled by the explosion of a charge placed in the tool and tired by a firing device comprising a ring pin actuated by a striker.

In order to protect users, some of said tools do not comprise any trigger device, but are so made that the striker carried by an actuating member is displaced simultaneously with said member, against a recoil spring, under the etfect of a blow or shock at the rear end of the tool, for instance a sudden push with the hand, which, in practice, makes it necessary to press the other end (front end) of the tool against the surface of the material into which the fastener is to be driven.

In some embodiments of the above mentioned known tools, the latter comprise a barrel removably assembled with a breech block and firing pin carrier slidingly located in an elongated housing partly surrounded by a slidable firing pin actuating sleeve, the relative movement of the said sleeve, which carries a tiring pin striker, with respect to the breech block being controlled by means ot` a Safety device comprising a system of longitudinal grooves and a pawl carried respectively by the elongated housing and the breech block.

The system of grooves comprises a iirst longitudinal groove and a second longitudinal groove having a section at right angles and intersecting the first groove, the arrangement being such that the pawl can be engaged in the second groove by imparting, by hand, a rotary movement to the elongated housing with respect to the breech block and the barrel, the length of the second groove enabling the said housing to assume, in relation to the barrel, a longitudinal position such that the striker can hit against the firing pin.

The present invention has for its object to improve the tools of the above mentioned kind in order to simplify their manufacture and their handling.

According to the invention, the slidable tiring pin actuating sleeve comprises a bottom and surround completely the rear part of the housing, the firing pin striker being secured to said bottom.

in order to permit a better handling of the tool, a grip is secured to said sleeve.

According to another improvement, the pawl integral with the breech block and ring pin carrier on which is removably mounted the barrel of the tool, the pawl cooperating with the safety groove system, is slidingly engaged with a longitudinal groove provided on the tiring pin actuating sleeve, so that the barrel and the sleeve are both rotatable with respect to the elongated housing.

Other features and characteristics of an improved tool will be gathered from the description hereunder, which relates to a preferred embodiment of the tool, given solely by way of illustration and shown diagrammatically on the accompanying drawing, on which:

Fig. 1 is a longitudinal radial cross-section of a projection device according to the invention;

Fig. 2 is a larger scale view of the groove system of the safety device;

Figs. 3 and 5 are two radial, longitudinal cross-sections showing two modifications of the barrel front end for the xing of special washers to the mouth of the tool barrel;

Fig. 4 is a plane view of the washer shown in Fig. 3.

in the specimen embodiment shownin Figs. 1 and 2, the tool comprises a barrel 1 of which the end opposite the projection orifice is provided with a tapped hole of larger diameter than that of the bore 2 of the barrel. In this tapped hole is screwed the end of a breech block and tiring pin-carrier 3 in which a rod 4, forming the tiring pin, can slide freely. The firing pin is not in the axis of the bore 2, but is slightly displaced towards one side. Between this tapped hole and the bore 2 of the barrel is a cylindrical housing which is co-axial with the bore and has a diameter which is intermediate between that of the bore and that of the tapped hole. This cylindrical housing takes a cylindrical cartridge carrier 5 through which the barrel is locked on the breech block 3. The cartridge 6 is placed inside the cartridge carrier, the collar 7 of the cartridge resting on a shoulder inside the carrier at the end of the carrier which is in contact with the breech block 3.

An outside elongated housing 8 is fitted over the barrel so as to be able to rotate and slide longitudinally. The length of this housing is such that it can enclose the barrel 1 from one end to the other. A spring 9 is inserted between the breech block 3 and the rear end of this housing so as to make the barrel project partially beyond the housing when the tool is not in use, as shown in the figure.

The housing is guided over the barrel by means of a lug constituted, in this particular case, by a screw 10 with guiding head i1, screwed radially into the breech block 3. This head 11 projects slightly outside the housing 8 through the grooves shown in Fig. 2. v

The projecting end of this head l1 is engaged in a longitudinal groove 12 of a firing pin actuating sleeve 13, to the end of which a tiring pin striker 14 is lixed coaxially. This striker comprises a threaded stem 15 screwed in the bottom 13a of the sleeve 13 and is accessible from outside. This axial striker passes through the end of the housing 8 and, inside this housing, has a wider part, or head, 16. A spring 17, stronger than the spring 9, is mounted inside the sleeve 13 between the vend of the housing 3 and the bottom of the said sleeve, and separates these two members from each other, the maximum space between them being limited by the head 16 of the striker which thrusts against the inside surface of the end of the housing 8. A butt or handle 19 is fixed on the sleeve 13 by means of two screws 20.

The system of grooves in the housing 8 is shown on a larger scale in Fig. 2. It has a longitudinal groove 21 of which the ends are shown by the lines A and B in Fig. l. The distance between these lines, or the length of the groove increased by the maximum possible advancev of the sleeve 13 in relation to the housing S, is less than the distance between the end of the firing pin 4 and the head i6 of the striker 14. It will therefore be seen that if the housing 8 slides forwardly over the barrel 1, compressing the spring 9 (for instance, owing to a blow on the projecting end of the barrel), the head l'of the screw- 1l) strikes against the end B of the groove 21, so that the tiring pin cannot get into contact with the striker 14 and it follows that there can be no accidental firing of the cartridge 6. In the same way, if there is an impact against the end of the sleeve 13, the latter is pushed forward longitudinally and, through the spring 17, the housing 8 is pushed back on the barrel 1, and this movement is stopped 3 by the end-B of the-groove21. In thisposition of the housing in relation to the barrel, the maximum pressure of the sleeve 13 against the spring 1'7, Whichit compresses completely,does not suice to causethestriker 14 to'hit the tiring pin 4.

ln'order to ensurethat firing lwill' take place'when it is desired to tire the tool, a transversal groove 22 has been madeinthe wall of lthe housingS'at'a point halfway alongfthe groove 21. This itransversal groove curves roundlinto alongitudinal'part' 23, the endof which is shown'by C in'Fig. l.

When the'head Il'of the` screw-10 is opposite the openingv inthegroove 21 leading into groove 22, that is tosay, between the lines Dland E on Fig. l, or A-l'Fig 2, it suices to rotate the housing S'relative to the barrelrl by hand, and this head 11 penetrates into the groove 22, then into the'groove 23, thus enabling the housing 8 to advance in sliding over the barrell, by compressing only the spring 9,until the head 11 of the screw 10 comes to a stop against the-end C of the groove 23. In thisl position the striker 14 travels far enough to hit thefiring pin 4.

A'iiared mouthpiece 26, intended to act as silencer and splinter screen, is slipped over the opposite end of the housingS and held in place by a keeperring 25. A rubberring 27 is placed inside thismouthpiece 26.

Instead of this flared'mouthpiecda cylindricalmouthpiece, which prolongs only the housin'g 8, can be mounted. A device 30, with a space fora washer inside, vis slipped over the mouth of the barrel 1 and fixed detachably, also by a keeper-ring,'29.

This tool is operated as follows: the barrel 1 is unscrewed to separate it from the `breechblock 3 and is withdrawnfrom Ythe housings. A dowelv pin shaped'fastener 32 comprising a pointed shank 35, a guiding head V34 and a shearable disk 33 integral with the head 34 (or removably secured to said head) and then a cartridge 6 are placed respectively in the barrel and in the cartridge charnber 6, and the barrel is replacedand fixed on the breech block 3. It is locked on the latter by means of thecarrier which clamps the disk 33 in the barrel and thus maintains the fastener 32. The outerend of the barrel 1 is then pressed against the vsurface of the material into which the fastener 32 is to penetrate, the workman holding the tool by the butt in his left'hand and keeping it strictly' at right angles to the said surface. By pressing on this butt, the workman causes the elongated housing 8 to slide along over the barrel 1 until the head 11 of the screw 10 is opposite the groove 22. With his right hand he thereupon rotates the housing 8 relative to the barrel 1, at the same time maintaining his pressure on the butt 19 to push the head 11 in the groove 22 and thenin lthe groove 23 thesleeve further along the barrel. The head 11' of the screw having beenbrought'back intothe groove' 23 by this rotating movement, the housing "continues to travel forward with respect to the barrel and the spring 9 is more and more compressed until the splinter. screen 26 also presses against the surface of the'material into which the fastener is to be driven, the length of the groove 23 being especially designed for this purpose. All the workman then has to do is to give the rear end of the sleeve 13 a fairly sharp blow with his right hand, in order to advance the sleeve 13 with respect to the housing 8 by compressing the strong spring 17 and cause the striker 14 to hit the tiring pin 4, the butt 19 held in the workmans left hand accompanying the sleeve in this movement. The explosion of the cartridge 6 forces the'fastener 32 out of the barrel 1 and into the material, where it becomes firmly anchored, the disk 33 or an annular portion thereofre- -maining in thev cartridge chamber from which it is removed when the barrel is unscrewed.

The operation is repeated for each fastener to be put in. When a washer is placed inside the. washer-collar 30, the point of the fastener perforatesthis washer and is thus centered by it when it leaves the barrel, this ensuring that the fastener is better guided and penetrates better into thematerial. lnaddition, that partof-the washer which is carried along by the fastener forms a collaret on the latter, restricting its penetration into the material.

The tightness between the cartridge chamber and the bore of the barrel is ensured 4.bythe disk 33 of the fastener 32. The saiddiskrests againstthe wall of thesaid chamber and is'placed beneath the cartridge carrier, so that it is held tightly by the cartridge carrier against the end of the cartridge chamber. `When the'cartridgeexplodes,tthel super-pressurewhich occurs at'the rear .end of the fastener 32 is suchthatV the 'disk' '33 is sheared and the fastener `is forced throughthe 4bore,ofthelnarreL In addition, the fastener 32 has a head 34, next to the disk and havingY anY outside 'diameterequal to the diameter of the bore of the barrel, whichzguidesit, and a portion 35, of a smaller diameter, ending in a point destined to penetrate completely into the material, the head 34 limiting the extent of penetration.

'in orderto limitthey extent of penetration still further and `'also to ensure-better guiding lCif-'the vfastenerfthe following modification may be provided.

As shown in Figs. 3'and 4,1a washer 36 can be placed on the mouth of -the barrel. 1,` this washerbeing kept in place by projections 38 of the barrel which lit into'holes 37. WhenV it leaves the barrel, the v'portion 35 of the"fastener perforates this washer 36, and the portion 34 cornes on top of it` and carries it along, the washer thus forming a collaret on the fastener, whichpresses firmly against the material into which the fastener is'driven.

Obviously, the sameresult could beachievedrby'means other than those shown diagrammatically in'Figs. 3 and 4.

Fig. 5 shows another modification in which a small washer 36a is placed in a lower-'recess of the barrel 1a. If it be'desired to usea larger washer, a special head 39 can be applied to the mouth of thebarrel instead of the device 30 shown in Fig. l, this head being provided'with a cavity '4D-which serves to take a larger washer 36h.

llt 'goes Ywithout rsaying that thesubject-matter of the invention is in no way limited to the'detailso'f embodiments represented or described, which'have been given merely by way of illustration.

What'l claim is:

l. An explosivelyl actuated fastener driving tool'comprisingz'a `breech blockga barrel removably secured to said breech block; afiring pincarried bysaid breech block; an elongatedhousingslidably guided over said barrel and said breech block 'and vable to perform a limited longitudinal movement'with respect thereto; spring means locatedbetween the -rear end of the said breech blockand the'rear end of the said housing fornormally pushing said yhousing opposite 'the front end 'of said barrel which 'normally projects Y"from thefront end of said housing; a striker having a front end insaid housing for .actuating said yiiringpin,A said 'striker and said housing having limited 'longitudinal slidable'movement relative to one another; "a tiring pin actuating'sleeve slidably guidedoVer the rearend 'portion'of lsaid .housing and' supporting said strikcr'for movement therewith; and a" spring, stronger than said first v'mentioned spring means and located between the rear'end of said housing and the-rear end of said'fsleeve, for normally urging back said sleeve and said strikerY with'respect to said housing, said striker pin being normally separated from said tiring vpin'a greater distance than-the" extent towhich said housing can move longitudinallywith respect to said barreL-and'said housingbeingrotatable relative tolsaid pin whereby `after said rrotatable movement the said striker may .be Ymoved'to -a 'position to f actuate the firing 2. A-tool `asr'clairued .inclaim 1further .comprising a butt, said-butt'beingsecured to the-tiring-pin actuating sleeve.

, 3. A tool as claimed inclaim 1, whereinfsaid breech block is provided witharadial screw havingia. projecting head, and said housing has two non aligned longitudinal slots, one in advance of the other and an intermediate curved slot joining said longitudinal slots and the rng pin actuating sleeve has a longitudinal inside groove, the screw head being received in said slots and entering in said groove, so that the groove in the sleeve and the slots in the housing move relative to the screw and the breech block.

References Cited inthe file of this patent UNITED STATES PATENTS Sopris Aug. 8, 1950 Temple Dec. 12, 1950 Temple Apr. 24, 1951 Temple Nov. 13, 1951 Temple Dec. 23, 1952 Walker July 21, 1953 

